June has been designated Invasive Species Awareness Month in our state, a time where educational efforts and information on invasive plants and animals becomes the focus.

What is an invasive plant species? In many cases, terrestrial invasive or exotic plants are brought into our landscapes as ornamental or garden plants. We think they are beautiful, different from everything else, something special, and we must have them. This is how it starts.

No checks and balances

Non-native species that are introduced into new areas are often resistant to any insect pests or diseases found naturally in the area and therefore thrive and spread quickly through suitable habitat.

As they become established and colonize new areas, most of these species will quickly smother or suffocate native wildflowers and grasses growing in the area. Because they have no natural predators to keep them in check, these invasive species can quickly gain a stronghold in our forest, grasslands, even our lakes, rivers and streams.

From there, a cycle of damage occurs that affects native wildlife, birds, reptiles and amphibians, mammals, insects and more. Entire ecosystems can be changed in just a matter of years when an invasive species moves in.

According to the Wisconsin Department of Natural Resources, about 42 percent of the native plant and wildlife species on the federal threatened or endangered lists are at risk primarily because of invasive species.

Left uncontrolled and free from containment, invasive species are spread by many means, including wind, water, wildlife, as well as human beings.

The law and you

In Wisconsin, invasive species are covered under the NR 40 rule, which makes it illegal to possess, transport, transfer or introduced certain invasive species in our state without a permit.

It is our responsibility as gardeners, as well as plant buyers and sellers, to be aware of every species listed in the rule as prohibited or restricted in our state.

The rule defines two primary categories of invasive species. Prohibited plants are those that are not yet in the state, or present only in a few places but are likely to arrive and cause environmental and/or economic harm. Restricted plants are those that are already widespread in the state and have a high impact.

How the law is enforced

The state Department of Trade and Consumer Protection is given the responsibility of inspection of state licensed nurseries and growers. If a business or organization is suspected to be selling potentially invasive plants, a complaint should be logged.

In addition to onsite inspections, all licensed growers and retailers in the states are periodically sent communication regarding the invasive species rule, as well as updated list of restricted and prohibited species.

Sound off on invasive species

Proposed changes to the rule include the listing of 15 new prohibited species, 32 new restricted species, as well as delisting a few species.

The proposed additions include many favorites, including landscaping plants such as Amur maple, wormwood or artemisia, Japanese barberry, Siberian pea shrub, Queen of the Prairie, yellow flag Iris, scarlet pimpernel, black locust, Japanese wisteria and garden Heliotrope.

Anyone with comments, feedback, suggestions or opinions on the rule or the proposed changes should contact the Wisconsin Department of Natural Resources via Terrell Hyde, DNR Bureau of Natural Heritage Conservation, 101 S. Webster St., Madison, WI 53707-7921. You can email comments to DNRInvasiveSpecies@wisconsin.gov. Comments must be postmarked no later than June 30.

Additionally, the Wisconsin DNR is holding two public hearings in the state regarding the proposed changes, one in Madison and one in Green Bay. The first meeting will be held at 4 p.m. June 17 at the Wisconsin Natural Resources building, 101 S. Webster St., Room G09, Madison. A second meeting is set for 4 p.m. June 18 at the Wisconsin Natural Resources Service Center at 2984 Shawano Ave., in the Lake Michigan Room, Green Bay.

—Rob Zimmer, Post-Crescent staff writer, writes Yard MD every Friday. He can be reached at 920-419-3734 or yardmd@postcrescent. com; on Twitter @YardMD.

ALIEN INVADERS

The following plants lead the list of invasive plant threats in Wisconsin. This is only a small sampling.

»Common and Glossy Buckthorn

»Garlic mustard

»Bush honeysuckle

»Purple Loosestrife

»Dame’s Rocket

»Wild parsnip

»Japanese or giant knotweed

»Phragmites

»Tansy

»Russian olive

»Multiflora rose

»Creeping bellflower

»Spotted knapweed

»Canada thistle

»Common and cut-leaved teasel

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KEYS TO INVASIVE PLANT CONTROL

Once an invasive plant moves in, there is no easy way to get rid of it. Eradication will likely be a multi-year, even multi-decade approach of constant monitoring, hand or mechanical removal and/or chemical eradication measures.

Here a few things you can do to help stop the spread:

»Never let invasive plants go to seed or set berries

»Inspect clothing and animal fur, as well as shoes and boots for seeds before leaving an infested area.

»Use native plant species wherever possible.

»Be on the lookout for invasive species and know how to identify them.

»Natural landscapes offer the best defense, so leave them alone.

»Respond aggressively to eradicate invasives on your property. Even one season without control measures will result in years and years of necessary work.